Insecticidal composition



l atentet l on 7, 1941 titltliddt uiicrt Go Guy, arir, ll elt, easier to h. l.

do Tout do Memos do Wet, a, corporation oil @ompany, Wihnington,

eiaware No Hragl dppliention l ipril as, laid, deriai tt h'l id lid Wins, (ill, lot-ti) This invention relates to compositions oi mat i ter useiul in controlling plant pests such as insects, iungi, and amlar organis, and provides means for increasing the eflectiveness oi rotenone and pyrethrum insecticides. More particularly this invention relates to composttions adapted for application to plant iolie and provides for efiective control of such persistent and resistant pests as red spiders. Specifically T have found that thiuram sulfides exert a pronounced efiect upon the toxicity of rotenone and pryethrum insecticides, and not only materially increase the emciency oi such insecticides hut also impart fungicidal and ovicidal properties thereto.

A wide variety of rotenone and pyret l mu insecticides are in common use and are among the most ehicient insecticides available. These insecticides, however, when applied in concentrations required for eflective control are quite en pensive and, moreover, in many instances tail to provide the proper measure of control.

at the present time, ior example, there is no entirely satisfactory control for red spiders on tender ioliaged plants such as room. Quite re" cently rose growers have begun to use sprays containing derris alone or derris together with sulionated castor oil, hut, while olotaining results somewhat superior to the earlier methods at control, have iound it necessary to moire ire uuent applications, about every tour to seven days, with high pressure spray euiupment, The results obtained, however, are only slightly hotter than those obtainable by spraying water alone and, moreover, the frequency oi applies. tion strongly encourages mildew to grow on the plants,

l have now iound that excellent control oil red spider can he olotained with rotenone insecti cides including cuhe, derrls, and eirtractives when a small amount oi a thiuram sulfide is in eluded in the spray miizture. By incorporating a small amount oi a thiuram sulfide in a rotenone insecticide T ain'ahle in many instances suitable for preparing to douhleits efliectiveness and at the some time i am ahle materially to reduce the numher oi applications required. in many instances a single application will sutiicc since my novel com position not only eii'ectively hills the adult spiders hut also destroys the eggs. This not only prevents reiniestation hut removes one oi the principalcauses oi mildew. "ll-lioreover, any mildew winch is present attire time at spraying is eiiectively checked, f

til'iiiie the thiuram suliides have proved to especially eiiective additions to rotenone insecticides for controlling red spider my invention is in no wise limited in this respect as I have found that similarly improved results are obtained with other plant pests such as aphids and thrips, and that the toxicity of pyrethrum insecticides may he increased in the same manner.

The efiect oi the thiuram sulfides in increasing the toxicity-oi pyrethrum and rotenone insecticides does not appear to be dependent upon any particular form of these insecticides. For example, the efiect has been observed with ground derris, ground cube, ground pyrethrurn flowers, camphor oil extracts of derris, and hydrocarbon oil extracts of pyrethrum flowers. Certain oils, however, have been found .to enhance the emciency of the base insecticide and superior results may be obtained by including a suitable oil along with the thiuram sulfide.

A large variety oi thiuram sulfides are suitable for the purposes of this invention. The follow ing may he mentioned by way of example: Tetraethylthiuram monosul'fide, tetramethylthiurarn disuliide, tetramethylthiuram monosuliide,

dimethylthiuram disulfide, symmetrical di 23% methyldiphenylthiuram 'disulfide, tetrabutylthiuram monosuli'lde, tetracyclohexylthiuram disulfide, tetrahenzylthiuram disulfide, tetraisohutyithiuram disulhde, methylene thiuram disulfide, dimorpholine thiuram disulfide, tetraphenyl'thiuram disulfide, and tetra-(.Z-ethylherryll thiuram disulfide.

The thiuram sulfide may be incorporated into rotenone or pyrethrum insecticides in any suitahle manner. Thus, the several ingredients may he dispersed in aqueous media to form dispersions suitable for spraying, or dissolved in a common solvent to provide solutions suitable ior spraying as such or in aqueous dispersions. Both the dispersions andthe solutions may he prepared in concentrated form suitable for use in preparing sprays. The ingredients may also he prepared in the form of dispersible powders sprays or for application to foliage in the form of adust. Othermaterials such as diluents, spreaders, and adhesives, as well as other insecticidal agents, may he included, V

In practice li prefer to employ suitable oil, preferably a fatty acid oil castor oil, corn'oil, soybean oil, peanut oil, and olive oil, as l have found that thetoa'icity', espechilly of rotenone insecticides, is materially illcreased hy the presence of such oils. For errr castor oil is much more ample, l" have round that such as coconut toil,

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effective in increasing the toxicity of derris than the sulfonated castor oil heretofore employed. Straight hydrocarbon oils exert a like influence on the toxicity of a rotenone insecticide, especially the powdered form such as ground derris and ground cube, and in general any insoluble oil will exert a like effect. By insoluble oils I mean oils like castor oil and unlike sulfonated castor oil which are not self-dispersible in water.

The insoluble oil may be emulsified with any suitable emulsifying agent and dispersed in the spray mixture. Preferably, however, I simply mix the insoluble oil with powdered derris or powdered cube in proportions to give dispersible powder. When the oil is mixed with derris or cube in this manner I have found that an emulsifying agent is unnecessary as the saponin in the ground derris or ground cube operates effectively to emulsify the oil when the mixture is dispersed in water. When a thiuram sulfide is also incorporated I may dissolve the thiuram sulfide in the oil and for this purpose prefer to employ such freely oil soluble sulfides as tetraethylthiuram monosulfide and tetra-(2-ethylhexyl) -thiuram disulflde.

The following examples, which are to be understood by way of illustration only, will serve to illustrate the effect of thiuram sulfides and insoluble oils on rotenone and pyrethrum insecticides. Unless otherwise noted, all sprays include a spreading and sticking agent in a final solution of 1-2000 (0.05%). The spreading and sticking agent was prepared according to the disclosure in the Tisdale and Flenner Patent Number 2,128,973, granted September 6, 1938. The derris used contained 4 per cent rotenone and 12 per cent extractives. The rotenone extract was a brown camphor oil extract containing 5 per cent rotenone and 20 per cent total extractives. The cube contained 4 per cent rotenone and 14 per cent total extractives.

EXAMPLE 1 Tetraethylthiuram monosulfide dissolved in an equal quantity of coconut oil was emulsified with sumcient quantity of water to form a 50 per cent emulsion. Solubilized casein was employed as an emulsifying agent. Sprays were prepared from the above composition with and without derris and were applied to bean plants heavily infested with red spider. The results as compared with derris alone are given in the following table:

The relative concentration in this and in the subsequent tables is given as the number of parts in 6400 of the total active ingredients ted under concentration.

These data show that by including a small amount of tetraethylthiuram monosulfide the toxicity of the derris is materially increased. Doubling the concentration of the derris had materially less effect than the substitution of Red spider on bean plants Cmmntmmn Per Relative Composition cent concen- Derris on Sulfide Derris 16-6400 62 16 0 16-6400 Coconut oil 4-6400 Tetraethylthiurem onosulfide 4-6400 Den-is 16-6400 Coconut oil 2-6400 Tetraethylthiuram mono- Coconut oil Tetraethylthiuram monosulfide sulfide 2-6400 Derris 8-6400 Coconut oil 1-6400 84 10 Tetraethylthiuram monosulfide 1-6400| These data show the remarkable effect of small amounts of tetraethylthiuram monosulfide in increasing the efliciency of derris sprays. Even with as little as one part of tetraethylthiuram sulfide in 6400 almost complete control is obtained with derris at 1-400. Even with derris diluted to 1-800 superior results were obtained with the same amount of the thiuram sulfide as compared with derris at 1-400.

EXAMPLE 2 The tests summarized in the following table illustrate the effect of oils. The oils were prepared in the form of a 50 per cent emulsion using a solubilized casein as an emulsifying agent and added to water suspensions of the derris in the concentrations noted. Oil emulsions of tetraethylthiuram monosulfide as described in Example 1 were added'to a. water suspension of derris in proportions to be equivalent to replacing one-half the oil with thiuram sulfide.

TABLE III Red spider on bean plants I Concentration Per Relative Composition cent concen- Denis on Sulfide km Coconut oil Tetraethylthiuram monosulfide Castor oil- Tetra ethylthiuram monosulfide Derris Soybean oil Tetraethylthiuram monosulfide These data show that while a substantial improvement is obtained by the oil emulsion alone, a still further improvement is obtained by replacing one-hall the oil with the thiuram sulfide, it was observed also that when derris plus the oil alone were employed reinlestation occurred ranidly after several days, whereas when the thiuram suliide was included rciniestation was markedly retarded, indicating that the composition containing the thiuram sulfide not only destroyed the adult spiders but also their eggs.

The following table illustrates similar results under conditions in which more eliective control was obtained with all compositions. The thiuram sulfide was added in the term of the coconut oil emulsion described in Example 1 and also in the form of a dry powder containing i per cent tetraethylthiuram monosulfide and 00 per cent Bancroft clay. in both cases i00 per cent control was obtained as compared with only partial control for the derris alone or the derris together with coconut oil. ilere again the coconut oil alone improved the effectiveness of derris, but the thiuram sulfide was still more edective even at one-half the concentration oi coconut oil. 1 Also,

a it may be noted that replacing halt the coconut dill oil with thiuram sulfide gave superior results.

TABLE Ill Red spider on cucumber plants EXAMPLE 3 The tests illustrated in the following table show the efi'ect of other thiuram sulfides on the toxicity of derris. The two methyl thluram sulhdes were prepared in the form of 'dispersible,

powders containing 80 per cent thiuram sulfide and about 20 per cent clay, and the tetra-(2- ethylhexyl) -thiuram disulflde was prepared as a coconut oil emulsion in substantially the same manner as described in Example i.

TABLE V Red spider on cucumber plums l lo comparative controls were run on the thiuram sulfides alone. In other tests, however, tetra.- methylthluram disulfide (clay) at 1-1600 gave per cent kill, tetra methyl thluram monosulflde control obtainable by thiuram sulfides alone is relatively inedective.

ElidiliPiE a Bar tests were conducted on Aplzis rumicis on nasturtiums. The results are given in the following table: 7

'lrintn Vi Aphids on austurtium pl nts I Concentratwn Per Relative Composition cent concen- Dorris on Sulfide km Derris 20-10000 99 i2, 8 Do -10000 75 s. 4 Coconut oil 5-10000 'Ietraothylthiuram 38 6 4 monosulfide (cmulaion) 5-10000 Dorris 10-10000 Coconut oil- 5-10000 TetrBethyIthiuram 100 9.6

monosulfidc (emulsion) -1 Dorris, 7 parts Tetraothylthiuram 100 6.4

monosmllide, 2 parts Dorris, 7 gents Coconut o 1 part.--" 100 6 4 Tetrsethylthiuram monosulfide, 1 part...

These compositions were prepared as described in Example 5.

These data show that the improvement in tensity over derrls by the addition of a small amount of thiuram sulfide is not confined to red spiders and that similar improvement may be obtained in connection with other plant pests. It is significant to note and compare the first and last two compositions in this table. The last two, tho containing only about a third as much derrls and only one and two parts innine thousand of the sulfide, gave equivalent results. Since 100 per cent kill was obtained with all three derrls thiuram sulfide sprays, it is evident that still greater dilutions may be effectively employed. Since, however, aphids do not presentany special problem of control, I prefer further to illustrate the eifect oi the thiuram sulfides on the toxicity of derris and other rotenone insecticides with reference to the more resistant red spider.

The promising results indicated by the above tests were confirmed in the held, In one case 150 rose plants infested with red spiders, aphids, and dew weresprayed with a combination of derrls' at i400 and tetraethylthiuram monoculflde (emulsion) i-3200. One hundred per cent of the aphids (Mucrostpbum roscc Liane) and 09 per cent at the red spiders were killed and the dew was checked. in another case a mixture at derrls at i-dllii and tetraethylthiuram monosde (emulsion) at item was applied by a grower to an entire range oi roses in his greenhouse. en applied under pressure oi" 300 pounds combination cleaned up the intestation completely without any lollaee injury. When reiniestation occurred the following tall, cube at 1-400 was substituted for the derris and the some excellent control was obtained, notwithstan the fact that cube is lmown to be less toxic than derrls. The plants so sprayed had only a low scattered living red spiders after two weeks and no relnlestation was observed within a period of three weeks;

In preparing sprays for field application it is desirable to incorporate the derris and the thinram sulfide into a single dispersible composition. These compositions may be prepared either in the form of dispersible powders or thick pastes, the latter being desirable when the derris is incorporated in emulsions of the thiuram sulfide dissolved in oil. A. fluid mixture should be avoided since the derris tends to settle out. Thick pastes of this type are of special interest since, as already pointed out, insoluble oils also improve the toxicity of the derris.

In this connection the thiuram sulfides have been observed to assert a favorable influence on the manner in which the derris disperses. When the thiuram sulfide is incorporated with the derris in the manner described above or in the manner as will be presently described, aqueous dispersions are more readily obtainable probably due to the fact that the heavier thiuram sulfide particles tend to drag the light, flufiy derris particles into the dispersion medium.

I have found further that the advantages due to the use of oils may be obtained to a marked degree by simply mixing derris powder with an oil or an oil solution of a thiuram sulfide in proportions such that the resulting composition is dry enough easily to be handled and weighed. A further advantage is obtained in that a dispersing or emulsifying agent is not essential. The saponin in the derris powder apparently performs this function. The proper amount of spreader and sticker, for example, about 2 per cent by Weight, may also be incorporated without such compositions becoming too wet and sticky to be handled and weighed. These compositions and their efiectiveness in controlling red spider are illustrated in the following example:

EXAMPLE 5 In the following tests, as illustrated in Tables VII and VIII, derris was mixed with tetraethylthiuram monosulfide alone and with tetraethylthiuram monosulfide dissolved in an equal quantity of coconut oil in the proportions indicated under concentration. Two per cent by weight of the spreader and sticker described above was included in the dry mixture and dispersed in water to give sprays having concentrations of 1-400 and 1-800. For comparative purposes a spray was also prepared by dispersing the emulsion described in Example 1 in an aqueous suspension of derris to give a comparable spray composition. In each of these sprays the spreader and sticker was added as required to give one part in two thousand.

TABLE VII Red spider on bean plants Concentration Per Relative Composition cent concen- Derris on Sulfide Denis Q. 9-3600 19 16 Do 7-3600 Tetraethylthiur m 62 16 monosulfide 2-3600 Den-1s"... Coconut oll 94 1 'Ietraethylthiuram 6 mnnn nlfidn 1-36) TABLE VIII Red spider on bean plants Concentration Per Rel! Composition cent ggg kill Denis Oil Sulfide tration Denis 1-200 53 32 19-7600 Do 7-7 Coconut oil 1-7200 97 8 Tetreethylthiuram monosulfide 1-7200 Den-is 7-8000 Coconut oil l 5-8000 90 8 Tetraethylthiuram mono do l 5-8000 Den-is 7-7600 Coconut oil 1 25-7600 92 8 Coconut oil l 5-8000 74 8 Tetraethylthiuram monosulfide (emulsion) l 5-8000 It may be noted that in every instance a marked increase was obtained by the addition of the thiuram sulfide, even when thederris is reduced to less than one part in one thousand. The beneficial efiect of the oil also is clearly demonstrated. While the per cent of kill is somewhat lower than indicated in some of the previous examples, this may be attributed in part to the small concentration of toxins in the spray and in part to the particular biological conditions obtaining. The particular merit of these compositions, however, is clearly shown in comparison with the last composition which in itself, as illustrated in Examples 1 and 2, has proved exceptionally efiective.

EXAMPLE 6 The tests illustrated in the following table show the efiect of various oils on the toxicity of derris and the eflect of replacing the oil with the corresponding oil solution of tetraethylthiuram monosulfide. Each composition was prepared in the form of a dry dispersible powder in the same manner as described in Example 5 and dispersed in water in the concentrations indicated.

TABLE E Red spider on bean plants I Concentration Per R 61 at Composition cent Denis on Sulfide m Sull'onnted castor oil. I: 89 16 'Ietraethyl thiuram Denis; 8-6400 g rgi o l 73 12 e 9.... 8-0400 Castor oil 47 10 Derrisn 8-6400 Castor oil 80 Tetraethylthiuram 12 monosulfide e gocoigut oil 60 12 err Coconut oil 52 10 Derris Coconut oil 81 Tetraethylthiuram 12 monosulfide. Denis 8-0400 Coconut oil 67 Tetraethylthiuram monosulfide EXAMPLE 7 Team x Red spider on bean plants Concentration Feb 1351ave Composition 015111; concur Extract Oil Sulfide tration 100 25 0 hotenone extraet,25% How H000 25% LU mu m LII: 3:2 gotenor m 25%--.

oeonu o Tetreethylthiurat monm W 14000 1 m 96 sulfide, 12.5% gotenozge fixtzraat, 12.5%-. oeonn o TawaethyummgmmmW 1-4000 2-4000 1-4000 95 6.4

sulfide, 12.5%

them the loreeolne tohle it will he nn erent thot the urem sulfide ot 1-0000 there the etl'eetiveness oi the rotenone extrect st 1-2000 how 00 er eentto toner cent. emonnts suhstentielly to donhlinc the eilectireness oi the rotenone since the per cent ms is equal to that ohtsined with twice the quantity of rotenone.

EXAMPLE 0 in this example e. per oil (65 secondsher holt) solution oi the rotenone extract containing hi eridine oleote to render the solution eell-dishersihle was used in preparing the spray. In one note eastor oil was added to make 05 per cent by weight of the composition, and in the other is like cunt of e 50 per cent solution of tetraethylthlurem monosulflde in castor oil. The tests were also repeated in the same manner with coconut 011. Since all'the components of the insetticide were olls'or of an oily nature the in secticidei notion attributable to the oils was overcome and the value of the thiuram sulfide clearly indicated. The tollowlnx table is illustrative:

lied wider on hens plants Per cent Composition killed Concentration v Rotenone entrust, 25% Castor oil, 25 77 7 0 Piperidine oloote, 30% Rotenone extract, 25% Castor oil, 12.5% Tetrnethylthiuram monosulflde, 12.5% Psremn oil, Piperidme oleete, 30% Rotenone extract, Coconut oil, 25% PM to q oil, so?

fide, 12.57 Para-Mn oil, Piperidine olcate,

The shove compositions were tested in very dilute sprays (ll-1000) in order to ovoid any possible meshing oi the edects oi the thiurum sulfide. No spreader end sticker was ,used. It ls significant to note that in the castor oil spray as little as one part in 12000 of the thiuram sulfide increased the per cent kill by thirty per cent, and that in case of the coconut oil spray the same amount of the thiurem sulfide increased the kill from $0 to 60. These results ere especially significent since at 1-12000 the thiuram sulfide has no measurable eflect on red spider,

'Ihe remarkable effect of the thiuram sulfide in increasing the toxicity of rotenone insecticides is not confined to such substance alone as similarly good results were obtained with ground pyrethrum flowers and pyrethrum extracts. The efi'ect o! the tetraethyltluuram monosulfide on the toxicity of pyrethrum' is illustrated in the following examples:

EXAMPLE 9 In this example tetraethylthiuram sulfide prepared as a coconut oil emulsion as described in Example 1 was mixed with ground pyrethrum flowers and tested on Ankh 'rumicis on nastur-- tiums. The results as compared with the ground pyrethmm-fiowers and the thiuram sulfide alone nre given in the iollo tohle:

Tests :1

Aphids on nesturtlnm slants Concentration Baler concentratlon Per cent kill Composition ethn e iloennut oil Tetroethylthiursm mono- !iulflde Groundpyrethrumilowers. Groundpyrothrum flowers Ground pyrethmm do were Coconut oil 'ietraethylthluram monosulflde EXAMPLE 1 0 Fly spray tests were also carried out with tetraethylthiuram monosulfide and pyrethrum extracts in kerosene solutions. These tests were carried out in standard Feet-Grady chambers. The following table illustrates the results obtained:

TABLE XIII Concentration" Per- Per- Composition cent cent Pyle Suldown kill thrum fide Tetramethylthiuram disulflde 1. 3 5 0 Pyrethrum 25 35 33 Tetramethylthiuram disulfide. 0.5 Tetramethylthiuram monosulflde 1. 7 ll 3 Pyrethrum 25 82 47 Tetramethylthiuram monosulfide.. 0. 5 Tetraethylthiuram monosulfide" 2. 0 24 5 Pyrethrum 25 86 33 Tetraethylthiuram monosulfide.... 0 5 Pyrethrum 25 21 Do 125 98 62 Pyrethrum content is given in milligrams of total pyrethrins per 100 cubic centimeters and the sulfide content in percent.

From the above data it will be apparent that, notwithstanding the relative ineffectiveness of the thiuram sulfides alone, even when employed in saturated solutions, substantial improvement in the toxicity of the pyrethrum is obtained both in the number of flies which are down at the end of ten minutes and the number of flies dead at the end of twenty-four hours.

While I have described my invention in detail and illustrated the numerous advantages thereof, it is to be understood that my invention is not limited in these respects but that such variation in the nature and proportions of the ingredients, the manner in which they are associated and applied as come within the spirit of the invention are intended to be included within the scope of the appended claims.

aaamea I claim:

1. A composition of matter selected from the group consisting of rotenone and pyrethrum insecticides having incorporated therein a thiuram sulfide.

2. A composition of matter selected from the group consisting of rotenone and pyrethrum insecticides having incorporated therein an oilsoluble thiuram sulfide and an oil.

3. A composition of matter, selected from the group consisting of rotenone and. pyrethrum insecticides having incorporated therein tetraethylthiuram monosulfide.

4. A composition of matter comprising a rotenone insecticide having incorporated therein a thiuram sulfide.

5. A composition of matter comprising a rotenone insecticide having incorporated therein an oil-soluble thiuram sulfide and an oil.

6. A composition of matter comprising a r0- tenone insecticide having incorporated therein tetraethylthiuram monosulfide.

7. A composition of matter comprising a rotenone insecticide having incorporated therein tetraethylthiuram monosulfide dissolved in a water-insoluble oil.

8. A composition of matter comprising powdered rotenone insecticide having incorporated therein an oil-soluble thiuram sulfide dissolved in a water-insoluble oil in proportions to provide a dry, free-flowing, dispersible powder.

9. A composition of matter comprising a powdered rotenone insecticide having incorporated therein an oil-soluble thiuram sulfide dissolved in a vegetable oil in proportions to provide a dry, free-flowing, dispersible powder.

10. A composition of matter comprising powdered rotenone insecticide having incorporated therein tetraethylthiuram monosulfide.

HUBERT G. GUY. 

